Demountable containers and bases and panel joints thereof



Nov. 11, 1969 c. E KRIDLE 3,477,604

DEMOUNTABLE CONTAINERS AND BASES AND PANEL JOINTS THEREOF Filed March 15, 1967 4 Sheets-Sheet 1 INVENTOR. CHARLESE. KRIDLE A TTORNE Y Nov. 11, 1969 c. E KRIDLE 3,477,504

DEMOUNTABLE CONTAINERS AND BASES AND PANEL JOINTS THEREOF Filed March 15, 1967 4 Sheets-Sheet 2 F G 4 7 cHARLz gx i u-f mag) ATTORNEY Nov. 11, 196 9 c. E. KRl-DLE 3,477,604

DEMOUNTABLE CONTAINERS BASES AND PANEL JQINTS.THEREOF Filed March 15, 1967 4 Sheets-Sheet 5 I INVENTOR.

10a/ CHARLES E. KRIDLE A T TORNE Y Nov. 11, 1969 c. E. KRIDLE 3,477,604

DEMOUNTABLE CONTAINERS AND BASES AND PANEL JOINTS THEREOF Filed March 15, 1967 4 Sheets-Sheet 4 2 a 0 z i 4 I g 5 q 206 Jr II I L 202 I W i INVENTOR. 210 I9 204 CHARLES E. KRIDLE A TTORNEY United States Patent US. Cl. 217--12 1 Claim ABSTRACT OF THE DISCLOSURE A demountable, typically rectangular parallellepiped container having readily separable top, bottom, and

four side panels. The top and bottom each have lips at their edges transverse to their planes to retain the side panels, when assembled, against lateral displacement. A displaceable side panel is grooved along each of its vertical edges to receive and retain the adjacent vertical edge of each adjacent panel. Steel bands around the container in planes parallel to the grooved panel secure the assembled container. Flexibility and resiliency of the top enable reasonable upward force on that edge of the top contacting the grooved panel to bend the top, when the band near that edge is absent, enough to release that panel from retention by the lips, allowing its displacement to open one side of the container. Upon release of the force on that edge, the top snaps back into plane configuration producing a stable, 3-sided, open container.

This invention relates to demountable containers and to bases and panel joints thereof usable as well in other organizations.

Certain prior art containers, such as conventional wood frame shipping boxes, are not only relatively expensive to fabricate but have a relatively unfavorable ratio of net volume to gross volume.

Containers which, because of a height exceeding say forty inches, are inconvenient to load and/or unload from the top, have, in certain prior art, been provided on one side with a generally conventional door for loading. Not only does this increase the cost of the container because of the labor of building a door into the container and the cost of the door hardware, but the hinges and latch typically protrude significantly and in locations where they are subject to expensive accidental damage by, for example, being sheared off by impact against the coaming around a hatchway when the container is being lowered into the hold of a ship.

An object of this invention is to provide a demountable container relatively inexpensive to fabricate and having an exceedingly favorable ratio of net volume to gross volume; which can be loaded and/ or unloaded through a side, i.e., through an entrance or opening which is closed by a side panel when the container is fully assembled, and which is stable when said side entrance is open; whose configuration is such as to minimize the chance of expensive damage in handling; and which has means on the top and bottom of the container for restraining that aforementioned side panel against motion between entrance-opening and entrance-closing positions; and in which container that side panel can be released from the restraint of the restraining means by raising, through 3,477,604 Patented Nov. 11, 1969 deformation of the top, that region of the top which is adjacent that side panel.

Aiiother object of this invention is to provide an interlocking panel joint, especially for use in containers, partitions, and the like, Which is of simple, relatively inexpensive construction, and which, while rugged enough to resist disabling damage in ordinary use, can, without destruction, nevertheless be readily and repeatedly reformed into condition for re-use after being deformed by mishandling during use.

Other objects, advantages, and novel features of the invention will become apparent from the following detailed description when considered in connection with theiaccompanying drawings wherein:

FIG. 1 is an exploded view of a preferred embodimerit of a container of the invention;

FIG. 2 is a fragmentary top view of the adjacent regioiis of the two side panels in the foreground of FIG. 1;

FIG. 3 is an axonometric view of the container of FIG. 1 partially assembled;

FIG. 4 is an axonometric view of the container of FIG. 1 completely assembly and secured;

FIG. 5 is an axonometric view of a lid or top suitable for containers of the invention and differing from the top of FIG. 1;

FIG. 6 is a fragmentary view of another lid or top for containers of the invention;

FIG. 7 is an axonometric view of still another lid or top for containers of the invention;

FIG. 8 is an exploded view of another preferred embodiment of a container of the invention;

FIG. 9 is an exploded partial view of another preferred embodiment of a container of the invention with top and bottom omitted for simplicity and showing a modified form of panel joint;

' FIG. 10 is a partly assembled, exploded view of one form of a panel joint construction of the invention, usable in containers of the type of FIG. 1 and also in bins, partitions, fences, etc.;

FIG. 11 is an axonometric elevation view of a panel which can sometimes advantageously replace panels such as 136 and 154 of FIG. 10;

FIGS. 12 and 13 are axonometric elevation views of panels adapted for zig-zag type of fences or partitions with interlocking panel joints;

FIG. 14 is an exploded view of another preferred embodirnent of a container of the invention with a side panel hinged to the top to constitute a loading door at one side of the container; and

FIG. 15 is an axonometric view of a support, usable as a pallet or as the base of a container, the load-receiving deck of which is elevated by spacers of which one is 3 trkough opening onto the load-receiving surface of the The demountable container of this invention is typically a shipping container, although it can be used simply for storage and, with usually some modifications for convenience of access, as a shelter. Typically, although not necessarily, the container comprises a base or bottom provided with spacers, such as blocks or runners or skids, to elevate the main body of the container above the surface on which it rests sufliciently to allow access for the blades of a fork lift or the like; four generally rectangular side panels; and a lid or top. To achieve the exceeding favorable ratio of net volume to gross volume,

which is most significant when regarded as the ratio of.

the volume usable by the contents to the volume of the exterior volume of the container computed according to conventional shipping tariffs, two opposite side panels can be made essentially simply of sheets of material such as plywood; the other two opposite side panels can be made essentially simply of sheets of material such as plywood, each sheet having associated with it, on those two of its opposite edges which are, for a substantial distance, coextensively adjacent to edges of the aforementioned first two sides when the container is assembled, groove-forming means, typically comprised of sheet metal or the like, for providing a groove to receive the adjacent edge of the adjacent side panel to create a juncture or corner resistant to entry of rain and pilferers; the top can be made essentially simply of a sheet of material such as plywood with means, such as sheet metal lips, flanges, or the like extending transversely to the plane of the sheet, to help retain top and sides in assembled relation; the bottom or base can, aside from its spacers, be made essentially simply of a sheet of material such as plywood with means, such as sheet metal lips or flanges or the like, to help retain base and sides in assembled relation, and with one or more of the spacers made, if appropriate, in the form of a trough principally of sheet metal or the like opening into the interior of the container and adapted primarily to receive a portion of an irregularly-contoured item of contents to minimize the overall height of the container. To load and/or unload the container one of the side panels having the groove-forming means is arranged to be essentially placeable into a position in which it closes the entrance at one side of the container and is displaceable from that position in such a way as to open that entrance completely and is typically restrained against motion of emplacement and displacement by the aforementioned lip or flange means. The container is usually secured by steel bands or straps or the like, spaced from one another on the container and passing around the exterior of the top, bottom, and the two first-mentioned sheet-like side panels. The displaceable side panel is released from the restraint of the lip or flange means by raising that end of the top which is adjacent the upper edge of this panel when the container is assembled. The top is constructed to be sufliciently flexible to allow for readily raising that end by reasonable force exerted on the top near that end to bend the top upward when the securing band or strap near that end is absent but the top is held fixed at a region remote from that end against movement in response to said reasonable force. By virtue of the remaining securing bands and the groove-forming members associated with the side panel opposite the displaceable panel, the remainder of the container is secured in stable, assembled configuration although one side is open. The top is made sufliciently resilient to return to its normal, undeformed configuration when the force is released.

Reference is now made to the drawings.

FIG. 1 shows an exploded view of one preferred embodiment of a container of this invention comprising a base or bottom generally indicated at 2, sides or side panels 4, 6, 8 and 10, and a cover, lid, or top 12. Elements 4 and 6 are essentially identical to each other. Elements 8 and 10 are essentially identical to each other. The base is shown as being made of a sheet of plywood or the like 14 with means upstanding from the edge regions of the sheet 14 for retaining the sides from undesired displacement when the container is in assembled or partly assembled configuration. The retaining means are in the form of lip means such as 16 and 18 which can conveniently be constituted by the upstanding flange sections of a frame of angle iron or the like fastened, as by screws (not visible) and cooperating T nuts 20 or otherwise to the sheet 14. If desired, the base is provided with skids or blocks 22 to facilitate maneuvering the container with a fork lift. Elements 22 can be removably attached to the base.

The side panels or sides 4 and 6 are shown as simply sheets of plywood or the like whereas the side or panel 8 has associated with it, in the regions of two of its opposite edges, means forming essentially identical grooves or channels 24 and 26 for receiving adjacent cooperating edges 28, 30 of panels 4 and 6 respectively, when the container is assembled. The means which form the groove or channel 24 are the edge 29 of a plywood sheet or the like 31, and flanges 32 and 34 of angle iron or the like 36 which is fastened to sheet 31 by any suitable means such as screws 38 and cooperating T nuts (not visible). The base or bottom of the groove or channel 24 is formed by the leg or flange 32 of the angle 36 or, specifically, by what can be called the inner or interior surface of the flange 32 since it faces the interior of the container when the container is assembled. One side of the groove or channel is constituted by the edge 29 of the sheet 31 while the inner surface of the leg or flange 34 of the angle bar 36 constitutes its other side. The width of the groove or channel 24, the distance between surfaces 29 and 44, the distance between surfaces 29 and 44, is sufficient to accommodate readily but snugly the thickness of edges 28 and 30 of panels 4 and 6. The depth of the groove or channel 24, as best shown in FIG. 2, is in this construction, determined by and equal to the thickness of the sheet 31 at the end or edge surface 29, the depth being in effect, the distance in FIG. 2 between the bottom or base of the groove constituted by inner surface 40 of flange 32 and the level of the opening or mouth of the groovenamely, the region occupied by an imaginary extension of the plane innersurface 42 of sheet 31 extended to intersect the inner surface 44 of flange 34 and bounded by the coextensive lengths of the surfaces 29 and 44. It is observed that the groove or channel 24 is generally U-shaped in cross-section although the surfaces 29, 40, and 44, part of which bound it, exhibit generally the shape of a I when the panel structure is viewed as in FIG. 2. The height of the flange 34 (i.e., theheight of the surface 44 as seen in FIG. 2) is preferably no more than about twice the thickness of the sheet 31 to facilitate minimizing the volume of the container in demounted configuration when sides 8 and 10 are overlapped with one another. The length of the channel or groove is essentially the distance, measured generally transverse to the depth and to the width of the channel, over which the surfaces 44 and 29 are coextensive.

As is apparent from FIGS. 1 and 2, the relative configurations of the transverse cross-section of the groove 24 and the corresponding cross-section of the side panel 4 are such that the two side panels 4 and -8 can be associated with each other to form a corner by relative motion between the two panels in which the region of the panel 4 in the vicinity of the edge 28 enters the groove 24 moving in a direction generally transverse to the length of the groove 24, as indicated by the shaft of the arrow, and in the sense reckoned generally from the opening or mouth of the groove toward the base or bottom 40 of the groove, as indicated by the point of the arrow. For the embodiment of FIG. 1, and also for certain other embodiments of this invention, this defines the relative configurations of the groove or channel of one side panel and the cooperating edge of the associated side panel juxtaposed with the first panel to form a corner. This excludes certain other types of corner engagements such, for example, as a dovetail groove along one side panel and a mating dovetail tongue along the associated side panel inasmuch as these two panels could be associ ated only by motion of the second panel relative to the first panel only such that the dovetail tongue enters the dovetail groove in a direction along or parallel to the length of the dovetail groove and not transverse to the length of the groove.

The cover or lid or top of the container, indicated generally at 12 in FIG. 1, is shown as made of a sheet of plywood or the like 46 with angle iron framing 48, conveniently made of sheet metal or the like, fastened to the sheet 46 around its periphery by any convenient means such as screws 50 and cooperating T nuts (not visible). That leg or flange 52 of the framing 48 which extends transverse to the plane of the sheet 46 serves to help retain the container in its assembled configuration against unintentional demounting by overlapping the outer portions of the upper regions of the side panels as viewed especially in FIG. 4. The flange 52 also serves to add considerable strength and resistance to bending to the cover by :virtue of the substantial second moment of area of the flange relative to the neutral axis encountered in the bending of the cover under its customary loading. To facilitate bending the top 12 sufficiently to spring up one end of it enough to allow for the placement and removal of a removable panel, such as 8, the flange or lip generally indicated at 52 is provided with gaps 53 between neighboring sections thereof 54 and 55. Conveniently this can be accomplished by simply making the framing 48- of two U-shaped parts 56 and 58. This incidentally results in gaps 59 in those flange portions 60 and 61 of framing 48 which are fastened to sheet 46.

In assembling the container of FIG. 1 for loading the side is stood on the base 14 snugly against the flange 18. Side panels 4 and 6 are then stood on the base 14 with their respective edges 62 and 64 inserted in grooves 66 and 68, respectively, of panel 10. The top 12 is then put in place resting on the top edges of the three sides. Two conventional steel bands 70 and 72 (FIG. 3) are tightened and clamped around the structure. This fivesided container, open at one side or end, as seen in FIG. 3, is stable and ready to be loaded from the open end. The grooves 66, 68 keep the panels 4 and 6 from falling inward or outward. The lip means 52, 16 and 18 restrain the three panels from undesired displacement that would tend to dismantle the container. During the loading of the contents into the container the top 12 would usually be in its generally plane, undistorted configuration as shown in FIGS. 1 and 4.

After the contents have been loaded into the container, the top 12 is bent by forcing the free end upward as shown somewhat exaggeratedly in FIG. 3. This can be accomplished by pushing upward by hand the section of angle framing indicated by the lead line fromv48 in FIG. 4 or lifting it up with a pry bar or the like resting on the top edge 74 of side panel 4 or the like as a fulcrum. The material of the sheet 46 is chosen to be sulficiently flexible, and the gaps 53 in the lips 52 are provided, both to make the bend upward of the top 12 relatively easy, i.e. under the, exertion of only reasonable or moderate lifting force. The free end must be maintained in its displaced position only high enough and long enough to permit the panelS to be installed to close its end of the container. Since the material of the top 12 is chosen to be sufficiently resilient to restore the top to its generally plane, undistorted configuration once the upward force distorting the top into the configuration of FIG. 3 is released, it is the safest to maintain the top in its bent configuraion by maintaining pressure on the pry bar or by inserting a block between, for example, the top edge 74 of panel 4 and the flange 52 as a Wedge to keep the free end of the top up. This minimizes the likelihood of the bent up portion of the top snapping down and catching the fingers of a workman resting on the top edges of any of the panels.

The panel 8 is placed, as shown in FIG. 3, with its lower edge on the base 2 within the confines of the retaining lips or flanges 16 and with the lower ends of the edges 28 and 30 of panels 4 and 6, respectively, being received in the grooves 24 and 26, respectively, of panel 8. Panel 8 is then rotated into an upright position with the grooves 24 and 26 receiving the entire lengths of the edges 28 and 30, respectively. The wedging block or pry bar or the like are thereupon removed and the top 12 snaps back into its generally plane configuration with the two corners seen in the foreground in FIG. 3 encompassing the upper corners of panel 8, as seen in FIG. 4, with the flange 52 assisting flange 18 in restraining the panel 8 against undesired removal. With certain embodiments, where the stiffness of the top 12 is not too great, a careful workman can safely close the container without the need of wedging block or pry bar by rotating the panel 8, as seen in FIG. 3, to a nearly upright position, then with one hand forcing up the free end of the top and holding it there, and, while it is so held, moving the panel 8 into completely upright position with the other hand, and thereafter releasing the top to snap down into retaining position.

To completely secure the container, a third steel band 76 is installed as shown in FIG. 4. In this configuration the container is completely assembled and loaded ready for shipment. Since all the panels 4, 6, 8, and 10 are shown being of the same height, all parts of the container fit snugly together and form a stable, strong structure. The angle iron pieces such as 36 give added strength and stiffness and protect the edges of the wood from damage, as well as resisting pilferage and entry of rain.

To open the container for unloading, it suflices to cut only the band 76 and simply reverse the aforedescribed manipulation to remove panel 8-; pry or lift up the free end of top 12; while it is up, rotate panel 8 out from the container into a position similar to that in FIG. 3, and then lift the panel 8 bodily away from the container. Alternatively, the panel 8 can first be lifted upward vertically from the position seen in FIG. 4, thereby pushing with it the free end of the top 12 into a sprung-up position such as that in which top 12 appears in FIG. 3. This lifting upward of panel 8 can be facilitated by handles attached to this panel and is continued until the lower end of the panel is clear of the lip 18. If desired, a wedging block can then be placed between, for example, upper edge 74 of side panel 4 and lip 52. The panel 8 is manipulated to rotate its lower edge away from the container and the panel is thereupon disengaged from top 12 and bodily removed from the container. This method is some times more convenient for unloading, especially for certain relatively tall containers used for granular bulk material or the like.

This construction is seen to provide a container with what can be defined as a simply and readily removable and replaceable loading door or panel which dilfers from conventional loading doors and panels in that it is not principally fastened, attached, connected, or joined in what is normally considered more or less permanent fashion to adjacent sides by such hardware as bolts, screws, nails, hinges, latches, or the like, but rather is principally restrained from undesired removal by retaining means such as lips 52, carried by the resilient top of the con tainer.

If the container is to be re-used at or near the point of unloading, it may be left standing with the bands and 72 intact, in which case it is serving essentially as a rigid container with one side or end 8 readily openable for unloading and loading and with the container adapted to be readily secured for shipment by merely replacing panel 8 and replacing band 76. The container still retains its adaptability for demounting by simply removing all bands 70, 72, and 76. In demounted configuration it can be shipped relatively inexpensively to a point of re-use since its demounted volume is quite small compared to its assembled volume. To minimize the demounted volume, the cover and base can be made to telescope together and, in certain models where the parts are appropriately proportioned, some, if not all, of the remaining parts, including removable skids, can be stored between the cover and base. In any event, side panels 8 and 10 can be stacked overlapped, face to face as they are oriented in FIG. 1, with, for example, flange 34 of panel 8, fitting into groove 66 of panel 10 and flange 78 of panel 10 fitting into groove 26 of panel 8. If the height of the projecting flanges on panels 8 and 10, measured from the bottoms of their respective grooves, is maintained at no more than twice the thickness of the sheet material of which the panels are made, then the overlapped stacked volume will be minimized.

As previously indicated, the invention comprehends the idea of a container top that can readily be bent up so that retaining means at one end of the top relinquishes its retention of a removable panel of the container and which top is sufliciently resilient to spring back to normal retaining position when the bending force is removed. To insure that only reasonable force is needed to bend the top sufliciently so that that end of the top adjacent the removable panel is displaced enough to allow removal of that panel, there is included in the concept of the invention the proper selection of material and cross-section thereof used at that region of the top where the required bending takes place. When flange or lip means of significant depth, such as 52 in FIG. 1, are used on the top for any or all of such purposes as to retain a container in assembled configuration, provide strength and rigidity, and help to make a rain- .proof joint between top and sides, then these means must be interrupted or rendered discontinuous at the region (e.g. 53 in FIG. 1) where bending takes place; for otherwise their material and cross-section are essentially invariably such as would require excessive force to bend the top enough to release the end panel and would cause the top structure permanently to deform so as to prevent it from springing back into normal configuration. FIGS. 5 and 6 show other preferred embodiments of container tops similar to that of FIG. 1 with different means of accomplishing discontinuity of the lip or flange means.

The cover or top 80 shown in FIG. 5 is essentially similar to that of FIG. 1 in that comprises a sheet 82 plywood or the like to which is fastened, by screws 84 or the like, an angle frame generally indicated at 86. The frame 86 can be of one piece or can be made effectively integral by welding or seaming at the corner joints the contiguous sections of angle stock, made of bent sheet-metal or the other suitable material. In forming the required discontinuity in the frame to allow for bending the top, notches 88 are cut in that flange or lip 90 that extends transverse to the plane of the top whereas, contrary to the construction in FIG. 1, the flange 92 which is fastened to the sheet 82, is left intact.

FIG. 6 shows a container top, similar to those of FIGS. 1 and 5, exhibited only in the fragmentary region where most bending occurs and whereat it differs from those others. Using primed reference numerals of FIG. 1 to indicate analogous parts, 46 is a sheet of plywood or the like, and '56 and 58' are separate U-shaped sections of framing fastened to 46 by screws 50' or the like passing through the flange portions 60 and 61, respectively, of 58 and 56. Instead of a gap such as 53, 59 in FIG. 1, the discontinuity between the frame sections 56', 58' occurs as an overlap generally indicated at 92 with the flange portion 55 lying outside the flange portion 54'. Although this embodiment shows no screws 50 or the like passing into the sheet 46' simultaneously through flanges 61' and 60 in the region 92 where they overlap, certain models of the invention do use screws through the overlap and find it feasible, but then it requires somewhat more force to bend the top for placement and removal of the removable panel.

If strength requirements demand a thickness of the sheet portion of a container top such as would, in the event that a single sheet of plywood or the like is used, render the top too stiff to permit of the ready bending contemplated by the inventive concept, then a modification of the top can be made to retain both the desired strength and bending characteristics. One such modified top is shown in FIG. 7, upside down to expose its interior and with part of its peripheral lip or flange broken away for better illustration of this tops construction. This top includes a sheet of plywood or the like 94 reinforced with additional pieces fixed thereto of plywood or the like 95, 96 and framed with angle 97 fastened to the elements 94, and 96 with any convenient means such as screws (not visible, passing through one flange of angle 97, and mating the T nuts 98. The top is generally similar to those in FIGS. 1, 5, and 6 and can have discontinuities such as 99 in the free flanges of its angle frame similar to the discontinuities seen in FIGS. 1, 5 and 6. The cross-section of the top in the region 100, where major bending is to occur, is thin enough (being constituted by primarily only the cross-section of sheet 94 in view of the gap 101 between 95 and 96), to allow for the required bending under only reasonable force applied, for example, downward (as viewed in FIG. 7, but upward in the normal situation when this top is n and assembled container) in the right hand portion of angle frame 97 while bands, or the like, such as 70 and 72 in FIG. 3, hold that region of the to remote from the region of the applied bending force fixed against movement in response to the bending force.

Each of the four major peripheral edges of the pieces 95 and 96 is spaced from its neighboring segment of the free flanges of angle frame 97 sufliciently to form a groove adequate to receive an edge of one of the four side panels when the container is assembled. One such groove is indicated at 102, being formed between edge 103 of element 96 and the segment 104 of the free flange of angle frame 97. Surfaces such as 103 and 105 serve to render the assembled container sturdier and more secure by offering opposition along their entire lengths against undesired displacement of the edges of side panels inward toward the interior of the container. The corners of the piece 95 and 96 are cut off to facilitate fitting the top and side panels together. A construction similar to that of this top can be used for the base of or bottom of a container according to the invention to provide for added strength, sturdiness, and security. In making the base or bottom, however, there is no need for gaps such as 99 and 101 and these can therefore be omitted. Of course, such a reinforced bottom with a peripheral groove can be used without necessarialy using a similar top, and vice versa, depending on the strength and security requirement demanded of each particular element of a container.

In FIG. 8 there is shown an exploded view of another preferred embodiment of the container of this invention in which corner cleats constitute the means on the top for retaining side panels against undesired displacement. This embodiment is generally similar to that of FIG. 1 and is illustrated with the two sides (constituted of simple sheets of plywood or the like) analogous to elements 4 and 6 omitted for clarity. The base is shown as made of a sheet 104 of plywood or the like with skids 106 (r movable if desired) to adapt the container for handling by fork lift. Corner cleans 108 of sheet metal or the like, fastened to the base by any suitable means, serves to retain lower portions of the side panels while similar corner celats 109, 110 on the sheet 111 of the cover or top retain the upper portions of the side panels. The top is essentially identical to the base except it has no skids. This container is used in the same way as that of FIG. 1. To assemble, the side panel 112 is stood on the base against its nearby corner cleats, the adjacent simple sheet side panels (not shown) are placed on the base with their respective end edges inserted one in each of grooves 114, and the top is placed to rest on there three sides with its corner cleats 108 encompassing the upper portions of angles 116. Steel bands, similar to 70 and 72 in FIG. 2, are then passed around the box and clipped in place lying preferably over the metal or the like of corner cleats 109 and of optional cleats 118 which protect the underlying wood from being cut by the bands. After loading the box, the free end of the top is sprung up in the usual way and the readily removable side panel 120 put in place, being retained there by cleats 110 which snap down over it as the bent top is released to spring back into normal, general plane configuration. The container is finally secured with a third steel band around it passing over cleats 110. It is evident that lips or flanges on the top projecting transverse to the plane of the top are amply provided, by virtue of the gaps between cleats, with the discontinuities needed to facilitate easy bending of the top. This embodiment is not as rainproof, per se, as that of FIG. 1 (although it, as .well as others, is easily made rainproof with waterproof, pressure-sensitive adhesive tape covering the junctures between parts) but because it uses less metal or the like in the fittings, it is less expensive and lighter weight. Depending on the height of the side panels relative to the length of the base, some or all of the side panels may fit between the top and bottom when the former is placed on the latter in the course of associating the several parts in demounted configuration of minimum volume for storage or shipment to a point of re-use.

FIG. 9 shows an exploded view of four side panels of a container similar to the showing in FIG. 1 and aimed at illustrating corner posts 122, 124, 126, 128 as a modification of the means associated with the side panels to form grooves or channels for receiving edges of adjacent panels when the container is assembled. These corner posts are identical to one another and can be made as described in US. Patent No. 3,266,656, of sheet metal, extrusions, or the like. In using these posts in assembling a container such as that of FIG. 1, the following procedure is used. The description uses primed numerals from FIG. 1 for analogous parts. Side panel is formed by associating corner piece 122 (and, in like manner, corner piece 124) with it by simply sliding an upright edge of plywood sheet or the like 33 into the groove or channel 130 in post 122. This is shown as already accomplished with corner post 124 and also, relative to sheet 31', with posts 126 and 128. Panel 10' is then placed on a base, such as 2 in FIG. 1, and panel 6' is placed on the base with its edge 64 inserted in groove 68'. Similarly the side panel 4 is placed on the base and has its edge 62 inserted in groove 66' of post 122. A cover or top such as 12 in FIG. 1, or any modification thereof, such as those in FIGS. 5, 6, 7, or 8, is now placed on top of the three sides and banded With two bands such as 70 and 72 in FIG. 3. After the container is loaded the side panel 8' is installed (in the way by springing up the free end of the lid) with grooves 24 and 26 of corner posts 126 and 128, respectively, receiving edges 28 and 30', respectively, of side panels 4' and 6. A third band, such as 7-6 in FIG. 4, completes securing the container after the top has been allowed to snap shut with its lip, flange, or similar retaining means overlapping the upper regions of posts 126 and 128. To open the container, a procedure is used essentially similar to that of FIG. 1. The third band is removed, that end of the top retaining panel 8 is raised so that its retaining means (lip or the like) are clear of the upper region of 8', and panel 8' is then, with its associated corner posts, tilted outward about its lower edge and bodily removed from the container.

It may be noted that the relative orientation of corner posts in FIG. 9 is particularly adapted for the convenient fabrication and assembly of a square container. With the mouth or opening of the deeper channel of each post, such as 66 of post 122, facing the opening of the shallower channel or groove of its neighboring post, such as 24 of post 126, and so forth in sequence, from post to post, it is then possible to make all side sheets (e.g. 4', 6', 33', 31,) of a square container identical. This avoids waste of time during assembly in deciding which sheet fits between which pair of posts. It is, of course, also possible to orient the posts so that opposite edges of each side sheet both fit into shallow grooves or both fit into deep grooves, and not one of each as shown in the case of 31. Furthermore, it is, of course, possible, if desired for strength purposes or other reasons, to lengthen the flanges forming the side walls of the shallow channels, such as 130, to make the depth of those channels equal to, or even greater than, that of the other channels such as 66'.

In FIG. 10 there is shown a panel joint construction particularly useful in the construction of containers of the general type shown in FIG. 1 but also useful in making bins, partitions, fences, and the like. The joint construction comprises a first panel, generally indicated at 132 and including a sheet of plywood or the like 134, and a second panel, generally indicated at 136 including a sheet of plywood or the like 138. The two panels are adapted to be associated to form a corner with two edges, one of each panel, such as 140 and 142, juxtaposed. To prevent unwanted separation of the panels when they are associated, retaining means are provided comprising flange 144 or the like of angle 146 fastened to sheet 134and flange 148 of angle 150 fastened to sheet 138 in the vicinity of edge 142. Flange 148 is seen to constitute a lip protruding from the panel 136 in a direction transverse to the lateral surfaces of 136. Edge 140 and the flange 144 form a groove or channel 152 to receive a portion of the panel 136 in the vicinity of and including the edge 142 when the two panels are associated. The portion received can be the entire length of the edge 142 but is illustrated in this embodiment as being only one segment thereof, The base or bottom of the groove 152 is formed by flange 153 of angle iron 146. The rela' tive configurations of the transverse cross-sections of the groove or channel 152 and the corresponding cross-section of that portion of the panel 136 which fits into the groove 152 are as defined in the description of groove 24 and its mating portion of side panel 4 in FIGS. 1 and 2. That is, the relative configurations of the transverse cross-section of groove 152 and the transverse cross-section of the portion of the mating portion of panel 136 received in groove 152 are such that the region of the panel 136 in the vicinity of the edge 142 to be received in groove 152 could, insofar as their relative cross-sections are concerned, enter the groove 152 by motion in a direction generally transverse to the length of the groove 152. When the panels 132 and 136 are associated to form a corner, the walls 140 and 144 of the groove 152 prevent unwanted separation of the two panels by motion in a direction transverse to these walls. That is, if FIG. 10 be envisioned with panels 132 and 136 associated (as are already panels 132 and 154) so that panels 154, 132, 136 form a three sided enclosure, then it can be said that walls 140 and 144 of groove 152 prevent panel 136 from falling outward away from the enclosure or inward toward the interior of the enclosure.

To associate panels 132 and 136, panel 136 is typically slid downward longitudinally in groove 152, with the corner 156 of panel 136 being the first to enter the groove at the upper end 158, as viewed in FIG. 10. When the association of the panels 132 and 136 is complete their appearance is analogous to that of panels 132 and 154 and flange 148 overlaps that lateral surface of panel 132 which can be called its exterior surface in the same Way as does flange 160 of angle iron or the like 162 of panel 154, In this association, the flange 148 extends in a direction transverse to the direction of the depth of groove 152 and overlies the panel 132 in such a position as to obstruct motion of panel 136 away from panel 132 in the direction of the depth of the groove 152 reckoned in the sense from the base or bottom of the groove 152 towards its mouth or opening, and the base or bottom of the groove 152 itself obstructs motion of the panel 136 relative to 132 in the opposite sense. The undesired separation of panels is thus effectively prevented with motion of panel 136 in either sense transverse to the generally plane or lateral surfaces of panel 132 being prevented by flange 148 and flange 153 and motion gen erally parallel to the major surface of 132 being ob- 1 1 structed by walls 140 and 144 of groove 152. In that particular embodiment shown in FIG. of this panel joint of the invention the lip 148 occupies a different portion of the length of edge 142 from that received in groove 152. Should groove 152 be extended to receive the entire length of edge 142, then the angle iron 150 could be simply deformed and enlarged to accommodate and overlie the adjacent regions of angle iron 146. This joint construction forms of any two associated panels such as 132 and 136, and of course with any added panels such as 154, a self-supporting stable structure which stably stands up without risk of falling apart, by itself, without the need for a lid and bands such as 70 and 72 in FIG. 3.

When the construction of FIG. 10 is used in a container generally of the type shown in FIGS. 1 and 3, the three panels 154, 132 and 136 are associated and placed stably standing on the base of the container. They form a container which has the advantage of being accessible for loading both from the top and one open end or side. The fourth side panel, to be installed usually after loading is completed, can be either of the type of panel 8 in FIGS. 1 and 3 or the type of 8 in FIG. 9. Any desired flexible, resilient lid or top of the invention such as shown in FIGS. 1, 5, 6, 7, or 8 can be used to close the container, being finally secured by steel bands or the like.

The joint construction of FIG. 10 can also be advantageously used for other purposes. For example, if two panels, such as generally indicated at 163 in FIG. 11 are used in place of panels 136 and 154 in FIG. 10 and two panels identical to 132, then a four-sided, self-standing, readily demountable rectangular enclosure can be assembled by simply associating the four panels in the manner shown in FIG. 10. Flanges 164, 165 are essentially identical and engage each of the two opposite panels similar to 132. The enclosure thus assembled can be regarded as being bounded by a section of fence constituted by the panels; it can be used as a bin or crib, either by standing on the ground or floor or by being set on a base to which it may be attached if desired by any convenient means; it can be set on a base such as those shown in FIGS. 1, 8, or the like and covered with a lid or top, not necessarily flexible and resilient like those in FIGS. 1, 5, 6, 7, 8, etc., but if desired, relatively rigid, such as that of an ordinary pasteboard shoe box or candy box, thus forming a useful demountable container adapted to be secured in assembled configuration by ordinary steel bands and adapted to remain stably assembled when the top is removed.

If it is desired to set up a zig-zag type of fence or partition, panels such as shown at 166 in FIG. 12 can be alternated with panels such as 132 in FIG. 10. Panel 166 is made of a sheet of plywood or the like 168 with essentially identical retaining flanges or the like 170, 172, provided by any convenient means such as angle iron pieces 174, 176, respectively, fastened to sheet 168. Flanges 170 and 172 both extend in a direction transverse to the lateral surfaces or plane of panel 166 but in opposite senses.

It is equally possible to make a zig-zag partition or fence using panels such as 178 in FIG. 13 alternated with panels such as 163 in FIG. 11. Panel 178 is comprised of a sheet of plywood or the like 180' having pieces of angle iron or the like 182, 184 fastened thereto to provide grooves or channels 186, 188 whose walls are for-med, respectively, by flanges 190 and edge 192 and by flange 194 and edge 196. The openings of the channels both face in a direction transverse to the lateral surfaces or plane of panel 178 but in opposite senses. Each groove or channel is adapted to receive an edge of a panel such as 163 in FIG. 11 or 136 in FIG. 10.

Panel joints of the type of FIG. 10 are superior to interlocking panel joints having relatively more complex crosssections such as a rib of T cross-section on one panel projecting from an edge of that panel to slide longitudinally into a mating groove of T cross-section on the edge of an adjoining panel. These latter interlocking elements usually are convenient to fabricate by only extrusion, are more delicate and hence more subject to being bent out of shape in use, are more difiicult to straighten out once they have been bent, and will withstand relatively little straightening without breaking off. The panel joints of FIG. 10 and the like can, on the other hand, be readily made of sheet metal such as sheet steel which, because of its configuration in the joint, is easy to straighten when bent out of shape, and because of its structure will withstand, if necessary, a great deal of reforming without breaking.

FIG. 14 shows an exploded view of another preferred embodiment of the container of this invention with the top and the side panel used for opening and closing the loading entrance hinged together. This embodiment comprises a base generally indicated at 198. It can be made in any way conforming to the concept of the invention, such as like the base in FIG. 8, but is shown as being similar to the base of FIG. 1 with sheet 200, of plywood or the like, and angle iron framing 202 or the like fastened to the sheet 200 and providing lips or flanges such as 204, 206 restraining the side panels against undesired displacement. The three side panels 208, 210, 212 can be any type within the inventive concept such as their counterparts in FIG. 9 or in FIG. 10 but are shown as similar to their counterparts in FIG. 1 with panel 208 being made of a sheet of plywood or the like 214 having fixed to its opposite edges angle iron or the like 216, 218. The inner surface of flange 220 of angle 216 is spaced from adjacent edge of sheet 214 to form the walls of a groove or channel (analogous to groove 66 in FIG. 1) to receive the inserted adjacent edge of panel 210, the latter being illustrated as already engaged in the groove so that the side panels 208 and 210 form a juncture at a corner. Similarly the opposite edge of sheet 214 coacts with the inner surface of flange 222 to form the walls of a groove, analogous to 68 in FIG. 1, to receive the respective adjacent edge of side panel 212.

The displaceable side panel 224, which can be disposed either to close off or open the entrance to the container used for loading and/ or unloading the contents of the container, is made generally similar to panel 8 in FIG. 1, being comprised of a sheet of plywood or the like 226 with angle iron or the like 228, 230 along opposite edges of sheet 226 and with the free flange of each spaced from its respective edge of sheet 226 to form therewith a groove analogous to 24 and 26 in FIG. 1 to receive, respectively, edges 232 and 234 and panels 210 and 212, respectively. To assist in manipulating the side panel 224 handles 236 may optionally be provided. The panel 224 is hinged to the top 237 by a hinge 238 preferably of piano hinge variety and of a type capable of 270 of motion.

The top 237 can be constructed in any desired embodiment conforming to the concept of the invention so that it is flexible enough to be, by reasonable force, readily deformed sulficiently to free the displaceable panel 224 from the restraint which keeps it from being moved into a position to open the loading entrance between edges 232 and 234 of panels 210 and 212, and resilient enough to return by itself to its original, undeformed configuration when the force is removed. The illustrated embodiment is similar to the top 12 in FIG. 1, being comprised of a sheet of plywood or the like 240 provided with angle iron frame or the like 242 along the three edges not occupied by hinge 238. To allow for the required ready bending of the top, the free flange or lip 244 of the angle iron 242 is rendered discontinuous at 246 and at the corresponding location on the opposite flange.

In assembling this container, the panels 208, 210, and 212 are juxtaposed and placed on the base as shown in FIG. 14. With the side panel 224 swung out as shown to avoid, striking flange 206, the top 237 is lowered down onto the three sides 208, 210, 212 and two ordinary steel bands 248, 250 (shown in fragmentary form for clarity), analogous to bands 70 and 72 in FIG. 3, are

tightened and clipped, thus establishing a stable threesided enclosure. The panel 224 can then be rotated further counter clockwise about hinge 238 until it comes to rest lying on the upper or outer surface of top 237, thus completely uncovering the opening or entrance between edges 232 and 234 to facilitate loading the contents into the container.

To close the container the panel 224 is then swung clockwise about hinge 238 approximately as far as it will go--until itstlower region strikes the exterior of lip 206. Then either by means of handles 236 lifting panel 224 upward and transmitting this upward force through hinge 238 to the free end of top 237, or by means of hands, or by means of a prybar or the like resting, for example on the top edge 252 of panel 210 near edge 232, the free end of top 23-7 is forced upward sufficientlyso that the lower edge 254 of panel 224 will clear the upper edge of flange 206 as the panel 224 is swung further clockwise into an essentially vertical position wherein the respective grooves formed by angles 228 and 230 encompass, respectively, the edges 232 and 234 of panels 210 and 212. The upward force on top 237 is then removed and its resilience returns to its original, generally planar, undeformed configuration as it comes to rest more or less uniformlypn the-upper edges (e.g. 252) of panels 208, 210, and 212, and also receiving support from panel 224 which has, simultaneously descended until its lower edge 254 rests on the inner or upper surface of the base 198 with the ldwer regions of angles 228 and 230 nested within their respective corners of angle frame-202. The hinge 238 on the top 237 and the lip or flange 206 then combine to restrain the panel 224 from undesirably being displaced into a position to open the entrance to the container. The container can be completely secured by attaching a third steel band analogous to band 76 in FIG. 4.

The open the container, the aforedescribed procedure is reversed. The third steel band is cut or otherwise removed. The free end of top 237 is raised by hand, by handles 236, or by prybar or the like, until the lower edge 254 of panel 224 clears the upper edge of flange 206, and the panel 224 is then swung counter clockwise about hinge 238 about 270 to come to rest on top of 237. This completely exposes one side of the container between edges 232 and 234 for unloading.

Although the container of FIG. 14 is somewhat more expensive than other preferred containers of the invention, because of the cost of the hinge and its installation, the maneuvering of the hinged side to open and close the container is relatively convenient. The configuration and location of the hinge are such as to minimize the likelihood of damage to it compared to the hardware on a conventional reusable shipping container having a loading door.

Certain items are so configured that in the condition in which, to form a package, they commonly are, or conveniently can be, mounted for shipment and/or storage on a generally horizontal surface of a support adapted for handling by fork life, one portion of the upper region of the item is appreciably higher above that horizontal surface than the remainder of the upper region of the item. The invention recognizes that if the item is so configurated that a portion of the bottom of the item corresponding to the projecting higher portion of the upper region of the item can be mounted on the support at a level below the generally horizontal surface, then the overall height of the package can be reduced to assist in minimizing the overall volume.

Similarly, if the lower boundary of an item has a plurality of projections by resting on which the item can be carried on the support, then the invention comprehends providing means on which to rest the plurality of projections with their lowermost regions at a level below the generally horizontal surface of the support. One such item is the motorbike, or lightweight motorcycle,

which typically has been packaged for shipment with the rear wheel resting on the normally generally horizontal supporting surface of the bottom of a container and with the front fork, from which the front wheel has been removed, also resting essentially on that horizontal surface. Even with the front wheel removed, the handlebars project appreciably above the remainder of the upper contour of the vehicle. The shipping charge is usually based on the gross volume of the package reckoned by multiplying its greatest height by its greatest length by its greatest width. The volume charged for is thus equal to that of a rectangular parallelepiped bearing those three dimensions. But the actual item may not, by far, occupy the entire space within this box-shaped volume, even when, in an effort to maximize utilization of the space,

certain parts of the item are detached and placed beside the remainder, as, for example, the detached front wheel of the motorbike placed beside the vehicle for packaging, Further carrying out the object of the invention of minimizing the ratio of the gross volume to the net volume of a package, the invention contemplates a support on which such irregularly configured items can be placed to form a package of minimal gross height and hence minimal gross volume and shipping charge, whether the package be comprised of the items palletized on the support or of the items carried within a container.

One preferred embodiment showing this feature of the invention is' the support indicated generally as 256 in FIG. 15. It is comprised of feet or spacers 258 and 2 60, and, fastened thereto by bolts, nails, Or other suitable means, a deck or floor 262, which may be made of a single sheet, as of plywood, or a plurality of planks fastened together in any convenient way such as by cross strips or planks. The assembly thus far described can serve as a pallet adapted for handling by fork lift. For additional strength or rigidity a second deck or floor can be attached to the underside of the spacers 258 and 260, such as pallet being then often called doube-faced.

The spacer 258 can be an ordinary wood block or skid having the usual function of helping to support the deck 262 and its load at a distance spaced above whatever surface spacer 258 rests on (whether it be the ground, a second deck formed by cross pieces spanning the lower surfaces of 258 and 260, or a warehouse floor, or the like) sufficiently to allow easy entry of the blades of a fork lift or the like beneath 262. The spacer 260 is provided with a cavity or hole 261 giving the spacer the form of a trough or well. Since the trough opens onto or communicates with the upper surface of deck 262, the cavity can be entered from that upper surface. In addition to the support and spacing functions of spacer 258, the spacer 260 has the function of receiving a significant portion of an item of irregular contour loaded on the support (such as the motorbike shown in phantom with a wheel lodged in cavity 261) to significantly reduce or minimize height of the package comprising the support and its load. The spacer 260 can be made of sheet metal or any other suitable material fastened. in any suitable way to the deck 262. To protect the goods being shipped against accidental damage from the blade of a fork lift, the ends of cavity 261 are plugged with blocks of wood 263 or the like fastened to deck 262.

The support can, in addition to being used as a pallet as just described, be adapted to constitute the base of a demountable container of this invention similar to those shown, for example, in FIGS. 1, 8, 9, 10, and 14. To this end the deck 262 is provided with means to retain the sides of such container against undesired displacement, illustrated as angle iron frame or the like 264 having lips or flanges 266 extending transverse to the surface of the deck 262.

Items of load such as motorbikes can be mounted on the base, as shown in phantom, and anchored in place by any suitable means such as blocks or strips of wood jammed against the load and fastened to the base and/ or the sides of the container. The sides of the container, such as those in any of the aforementioned figures, are placed on the base around the load, being restrained by the flanges 266, and then the top, preferably of a size to telescope with the base and of any suitable variety, such, for example, as those shown in the several figures of the drawing, is placed down on top of the sides and secured in place, typically by steel bands such as shown in FIG. 4.

For purposes of illustration only, FIG. 15 shows a motorbike, prepared for shipping by having its front wheel removed according to conventional practice. To minimize the overall height of the package for shipping this item, it is appropriate to form only the cavity or depression 261 in the form of a trough since the form is adapted to receive a wheel of the motorbike. To receive the front fork of the motorbike, to lower the front end of the bike, it sufiices to provide cavities or wells 268 by boring, milling or the like through the deck 262 into the spacer 258.

If the contours of the particular motorbike happen to be such that no effective decrease in the overall height of the package would be achieved by lowering the bottom of the front fork below the level of the upper surface of deck 262, then of course the wells 268 can be omitted and the fork rested on the surface of 262.

The invention also contemplates the use of a plurality of spacers in the form of troughs. For example, for packaging a small automobile having a generally regular upper contour with no unique salient projections it is useful, for minimizing the maximum height, to use a support with two trough-type spacers, one to receive the front wheels and one to receive the rear wheels. As well as receiving parts of relatively large items, such as wheels of vehicles, trough-like spacers such as 260 can be loaded with bulk material or with relatively small items in their entirety thereby effectively improving the ratio of gross volume to net volume of the package for these products also.

Although the materials of which the parts of this invention are made have usually been described as plywood and sheet metal, obviously other materials can be used such as plastic, various laminates, etc. Although certain parts, e.g. side panels, are described as sheets, they can obviously be made in composite form by fastening several separate pieces together. Similarly, other parts shown as composite could be made integral. For example, a top or lid such as 12 in FIG. 1 or 86 in FIG. 5 could be made of a single piece of sufficiently flexible and sufliciently resilient sheet metal notched or slit at the corners to facilitate bending the peripheral portions of the sheet to form flanges or lips and to form trihedral corners, and with the flanges or lips notched or slits, as at 53 or 88, to facilitate beinding the top to emplace and displace the displaceable side panel. Such a top could be generally called a pan. Similarly, bases such as shown in FIG. 1, 8, 14, and can be made entirely or largely of a single piece of metal. Most parts are illustrated as imperforate for better protection of the contents of containers against rain, pilfering, or other damage but obviously perforated materials can be used such as expanded metal and the like when preferred for reasons of lighter weight, visibility of contents, etcetera. Although screws are typically shown to fasten parts together, obviously rivets, adhesives, or other fastenings can be substituted.

Although the illustrated embodiments shown containers generally in the form of rectangular parallelepipeds, the principles of the invention can be embodied in containers of other shapes such as polyhedrons in general, including those having a number of sides different from six and including those comprising one or more sides whose lateral surfaces are curved rather than being essentially planar.

Throughout this application where mention is made of the top or bottom of a container or of elements extending upward or downward and the like, it is to be understood that these terms of reference are used only for convenience in explaining the construction and use of the invention. Actually the typical container of the invention may find itself stood on an of its surface so that, in efi'ect, any surface can be the top or bottom. Should the container of the invention be so oriented that the deformable, resilient element is located to serve as the bottom, then to open the container the free, displaceable end of this element can be anchored against movement relative to the ground with the region of this element Where bending is to occur, resting on a fulcrum and the container can be tilted around the fulcrum to spring open the free end of the resilient element and the displaceable side panel can thereupon be displaced into open position.

The illustrated embodiments show the adjacent edges of adjacent side panels essentially encompassed along the entire length of their junction by groove-forming elements or the like, e.g. angle iron. Although this is advantageous to protect the juncture against entrance of rain or attempts at being pried open by would-be pilferers, the length of the corner-encompassing elements need be only enough to retain the adjacent panels from unwanted separations.

What is claimed is:

1. A demountable container comprising a base, a top, and four side panels, generally rectangular in shape and forming with said top and base a container generally in the shape of a rectangular parallelepiped;

one of said side panels, adapted for ready displacement between a position where it closes off an entrance to said container and positions where it opens said entrance, being provided with means disposed along opposite side edges forming grooves, each groove to receive, respectively, an edge of an adjacent side panel to form a juncture with said adjacent side panel;

the side panel opposite said displaceable panel forming two corners, one each in cooperation with each of its neighboring said side panels, each corner being created by the juxtaposition of an edge of said opposite side panel with an edge of a neighboring side panel; each said corner comprising means on one of said side panels forming a groove along one of said juxtaposed edges, said groove and said received edge being so relatively configured that said groove can receive said received edge by motion of said received edge into said groove in a direction transverse'to the direction of the length of said groove;

means of said top and on said base to restrain said displaceable side panel against undesired displaceable side panel against undesired displacement into entrance-opening position when said container is assembled; and

lip means extending transverse to the lateral surfaces of said top and said base to overlie exterior lateral surfaces of said side panels when said container is assembled to keep said side panels, top, and base against undesired relative displacement and thus to constitute, at least in part, said restraining means for said displaceable side panel;

an edge of said top being disposed adjacent an edge of edge of said displaceable side panel when said container is assembled;

said top being constructed to be sufficiently flexible so that, by applying reasonable force to said top in the vicinity of said edge of said top in a direction to raise said edge, while a region of said top remote from said edge is fixed against motion in response to said reasonable force, said top can be deformed sufiiciently, by bending said top enough to free said displaceable side panel from restraint of said lip means, so that thereby said displaceable panel is released from restraint by said restraining means against displacement to the extent that said displace- 1 7 1 8 able panel can be disposed in entrance-opening posi- References Cited tion; T said top, in order to be rendered thus sufficiently flex- UNITED STATES PATEN s ible, being comprised of sheet material and with any 996,967 7/1911 Bradleylip means on said top having an elfective discon- 5 1,218,628 3/1917 217 11 tinuity disposed in the region where the greater part 2,633,982 3/;953 Addlson' of said bending is to occur, said last mentioned 2578644 12/ 951 Maumer 217' 65 region being located intermediate said raisable edge FOREIGN PATENTS and Said fixed region of Said P d 545,024 5/1942 Great Britain.

said top being sufliciently resilient to return of itself 10 776,000 10/1934 France to its underformed configuration when said force is removed. RAPHAEL H. SCHWARTZ, Primary Examiner 

